PROPOSAL OF A NOVEL FORMULA TO CALCULATE DOMINANT WAVELENGTH FOR COLOR OF RED WINES

Dominant wavelength is a representative variable of the hue useful for the characterization of the colour of red wines. It is usually obtained through a conventional graphical method on the CIE 1931 (x,y) diagram. In this work, three alternative formulae for calculating dominant wavelength are checked on two sample groups of red and rose wines which consist of 109 Spanish wine samples and 66 samples taken from authors in the reference list respectively. A novel polynomic quotient expression obtained by applying the 'derivative-free nonlinear regression method' is proposed for an accurate calculation of dominant wavelength.